The invention relates to a rotary switch configuration for a household appliance, which configuration has a rotary knob that is seated in a cutout in an appliance panel and is firmly connected to an actuating shaft so as to rotate with it but move axially, the shaft transmitting the rotary movement of the rotary knob to the switching shaft of a switching unit mounted behind the appliance panel.
A configuration is disclosed by German Published, Non-Prosecuted Patent Application DE 198 32 089 A, in which the actuating shaft firmly connected to the rotary knob so as to rotate with it can be plugged onto the switching shaft of the switching unit and is carried by the latter. The rotary knob, itself, is coupled to the actuating shaft through a cardan joint. By the cardan joint, an axial offset occurring because of fabrication tolerances between an opening in the appliance panel that accommodates the rotary knob and the switching shaft of the switching unit is compensated for. However, the mobility provided by the cardan joint leads to the rotary knob being able to move radially, corresponding to the play existing between its outer circumference and the inner circumference of the opening. It is, therefore, possible for the rotary knob to rub on the inner circumference of the opening.
It is accordingly an object of the invention to provide a rotary switch configuration for a household appliance that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and that provides exactly central and wobble-free guidance of the rotary knob in the opening.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a rotary switch configuration for a household appliance with an appliance panel defining a cutout and having first and second opposing sides, including an actuating shaft having an axial direction, a rotary knob to be seated in the cutout at the first side of the appliance panel, the rotary knob being firmly rotatably connected to the actuating shaft for rotation with the actuating shaft and being movably connected to the actuating shaft in the axial direction for axial movement with respect to the actuating shaft, a switching unit being mounted opposite the rotary knob at the second side of the appliance panel, the switching unit having a switching shaft, the actuating shaft being connected to the switching shaft to transmit rotary movement of the rotary knob to the switching shaft, and a bearing device adapted to rotatably mount the actuating shaft to the appliance panel.
According to the invention, the actuating shaft is rotatably mounted on the appliance panel by a bearing device. As a result of mounting the actuating shaft on the appliance panel, exact central alignment of the rotary knob with respect to the opening, likewise provided on the appliance panel and accommodating the rotary knob, is possible. A wobble-free configuration of the actuating shaft is achieved by the bearing device.
With the objects of the invention in view, in a household appliance having an appliance panel defining a cutout, the panel having first and second opposing sides, there is also provided a rotary switch configuration including an actuating shaft having an axial direction, a rotary knob being seated in the cutout at the first side of the appliance panel, the rotary knob being firmly rotatably connected to the actuating shaft for rotation with the actuating shaft and being movably connected to the actuating shaft in the axial direction for axial movement with respect to the actuating shaft, a switching unit being mounted opposite the rotary knob at the second side of the appliance panel, the switching unit having a switching shaft, the actuating shaft being connected to the switching shaft to transmit rotary movement of the rotary knob to the switching shaft, and a bearing device rotatably mounting the actuating shaft to the appliance panel.
It is particularly advantageous to mount the actuating shaft rotatably by a ball bearing because a ball bearing has particularly little play and maintains this property even over a long period of use.
Assembly advantages result from the fact that the ball bearing is disposed in a bearing support that can be fixed to the appliance panel. Such a bearing support can be configured as a bearing ring that can be inserted into a bearing opening in the appliance panel. Such a bearing ring can be inserted in a simple way into a bearing opening provided on the appliance panel. In such a case, the bearing ring can be mounted in the bearing opening by latching elements provided on the bearing ring. Therefore, only one operation is required to fit and fix the bearing ring in the bearing opening.
Furthermore, it is advantageous for there to be provided on the bearing ring a collar that runs in a cone shape and projects towards the rotary knob. Such a collar constitutes a centering aid during the mounting of the actuating shaft.
Fabrication generally leads to an offset between the center of the switching shaft of the switching unit and the center of the actuation shaft. It is, therefore, expedient to couple the actuating shaft to the switching shaft by a coupling device that compensates for an axial offset. This may be achieved, in a constructionally simply way by configuring the coupling device as a plug-in cardan coupling.
In accordance with a concomitant feature of the invention, the coupling device has a slot and a pin.
Other features that are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a rotary switch configuration for a household appliance, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.